低成本室内照明无线控制系统研究与实现

在物联网大力发展的背景下,基于ZigBee无线传感网络设计了一种室内照明无线控制系统,介绍了其系统结构,并对其工作原理和工作过程作了较为详细的分析。这种无线照明控制系统可应用于教室、会议室等单个大房间,并且具有低成本、功能强大、安装和维护方便等特点。     

无线城市应用平台建设方案

文章介绍了无线城市的发展历程,分析了无线城市业务及应用平台建设思路,提出了无线城市运营思路,并对无线城市的发展进行了探讨.     

基于nRF905的智能照明控制系统

本文以Atmega16单片机和无线射频模块nRF905为核心,给出了一种基于无线局域网络的智能照明控制系统的软硬件设计.该系统采用RS232总线与PC上位机通信,通过无线射频收发模块与教室照明控制单元进行命令传输,实现短距离、多节点的无线控制.     

无线传输发射台站应急指挥体系建设

本文首先阐述了无线传输发射台站建设应急指挥体系的必要性,随后从五个方面详细分析介绍了无线传输发射台站建设应急指挥体系所具备的必要条件.     

基于WLAN的无线城市建设研究

随着国家信息化建设的不断发展,无线城市作为城市信息化建设的一项重要举措,已成为衡量一座城市竞争力的重要标尺.从无线城市网络建设出发,详细阐述了网络建设过程中网络规划、网络组网等环节,并对研究成果加以提炼,结合工程实际,对在某市的实际建设案例情况进行了简要介绍.希望能为以后的无线城市建设提供一定的参考价值.     

RASYS无线接入通信系统的建设与维护管理

介绍了我国农村通信发展状况和适于发展农村通信的无线接入网的发展目标及网络结构、号段规划情况,分析了建设无线接入网应注意的问题,介绍了华为RASYS无线接入网开通时遇到的障碍和进行处理的方法.     

无线传感器网络在军队指挥自动化建设中的应用

介绍了无线传感器网络的组成,讨论了无线传感器网络在军队指挥自动化建设中的具体应用,并分析了所面临的问题.     

ZigBee传输技术发展和建立教室照明灯智能控制系统

电费是学校必不可少的费用支出,各个学校都存在电能浪费现象,教室内照明灯电能浪费尤其严重,高等学校教室内出现“灯比人多”的现象比比皆是;节约能源,减少支出,实现教室内照明灯人性化管理必须纳入学校“节源开流”日程之内,建立ZigBee无线网络传输教室照明灯智能控制系统势在必行.为了有效节约学校教室照明灯用电浪费问题,本文设计的以ZigBee无线传输网络控制的教室照明灯智能系统,通过人数采集器统计教室内区域的人数,利用光敏传感器模块实现了对教室光照亮度的检测调节,满足了教室内照明灯需求的前提下成功地避免了不必要的照明灯电能的损耗.     

浅析地面无线数字电视广播系统建设

地面无线数字电视发展迅速,特别是随着国标的出台,地面无线数字电视的发展将迎来新一轮快速发展的时代.发展地面无线数字电视,是加速推进广播电视“村村通”工程的有效方式.首先概述了地面无线数字电视,然后介绍地面无线数字电视的优势,最后从建设需求、标准选择、系统结构和组成、信号覆盖情况等多方面,阐述新余市广播电视台的地面数字电视广播系统建设情况.     

ZigBee传输技术发展和建立教室照明灯智能控制系统

电费是学校必不可少的费用支出,各个学校都存在电能浪费现象,教室内照明灯电能浪费尤其严重,高等学校教室内出现“灯比人多”的现象比比皆是;节约能源,减少支出,实现教室内照明灯人性化管理必须纳入学校“节源开流”日程之内,建立ZigBee无线网络传输教室照明灯智能控制系统势在必行.为了有效节约学校教室照明灯用电浪费问题,本文设计的以ZigBee无线传输网络控制的教室照明灯智能系统,通过人数采集器统计教室内区域的人数,利用光敏传感器模块实现了对教室光照亮度的检测调节,满足了教室内照明灯需求的前提下成功地避免了不必要的照明灯电能的损耗.     

Progress in electrophotography in Western Europe

A review is given of the progress in electrophotographic science and technology in Western Europe during the years 1967 to early 1971. University research work is mainly directed towards two areas: 1) the electrical and physical properties of photoconductors, such as selenium, chalcogenides, oxides, and organic materials; and 2) the sensitization of these photoconductors. Industrial research teams report on the preparation of electrophotographic layers on development and on image evaluation. A bibliography including scientific papers and patents published on this subject during said period completes this review.     

智能通信在楼宇自控系统中的应用

随着计算机技术、控制技术、通信技术及信息技术的飞速发展,人们对生活、办公环境安全性、舒适性的要求日渐增长,智能建筑应运而生。楼宇自动化控制系统是智能建筑的一个重要组成部分。通过结合具体的智能楼宇控制工程项目,在介绍系统概况的基础上,给出了系统的总体设计方案及子系统的监控方案,具有一定的实用价值。     

Advances in millimeter-wave subsystems in Japan

The authors describe the development trends and results of millimeter-wave systems in Japan in such fields as communication, radar, and measurement systems. The applications included are the W-40G waveguide transmission communication system, an automobile traffic control system using the 60-GHz band, a collision avoidance radar system for an automobile, a plasma electron density measuring system, and satellite communication. The authors describe the development of devices such as high-power FET amplifiers, traveling wave tube amplifiers (TWTAs), IMPATT amplifiers, low-noise amplifiers, and monolithic microwave integrated circuit (MMIC) devices used in constructing the millimeter-wave systems     

中国带电清洗技术的突破

一、电路故障的成因 通常,由于空气的污染和设备所处的环境及管理条件不同,空气中的灰尘、油污、酸碱及其气体、盐分、潮气、炭渍、金属尘埃、各种机械杂质等污染物质,不可避免地吸附在电路表面及其它部位,加之静电累积和在电场力的作用下,污秽的累积不断加重和变得牢固,各种污秽牢牢附着在线路表面,深层及各部位。灰尘、油污、酸碱及其气体、盐分、潮气、炭渍、金属尘埃、各种     

Telecommunications in Malaysia: diversity in adversity

The telecommunications industry in Malaysia has experienced a tremendous transformation in just over a decade. The government-owned Jabatan Talikom, which hitherto operated the network, was incorporated in 1987 and subsequently privatized a few years later, with a majority share holding by the government. The regulatory aspects were spun off under the slim looking JTM. This marked the beginning of liberalization, and many new players entered the fray. This article reviews the telecommunications infrastructure and services available in Malaysia and visits some of the telcos offering these services. Some pertinent issues affecting the industry are also discussed     

Losses in small-radius bends in single-mode fibres

Refractive index profiles and mode field radii determine small-radius bending losses in single-mode fibres. Losses in six different types of fibres were measured in bends with radii ranging from 1.25 to 8 mm. The results show that a refractive index depression in the core centre reduces the bending-loss sensitivity.<>     

Rearrangements in cell populations in malignant growth

It is emphasized that one of signs of malignant growth is heterogeneity of cell population which arises at the earliest pretumour stages and determines the character of tumour progression. At the same time by means of selective influences on population of malignant cells it is possible to change their quantitative correlation and to obtain rearrangement of the normal cell interrelations. Initiation of the tumour, its progression and regression are considered on the basis of the population-cell rearrangement, typical of each of them separately. The concept of the unity of the carcinogenesis and anticarcinogenesis processes is also formulated.     

General Trend in Electrical Communications in Japan

Systems are currently being designed for higher reliability and greater economy. Larger transmission capacity is required to meet a rapid increase in recent communication demands instigated by the introduction of video and information communications facilities. More flexibility, to deal with the variety of communication modes to come, and smaller hardware dimensions, to overcome situations caused by the high population density, seem to be particularly sought in the communication technology of Japan. Research and development concentrate on these objectives. The following is an explanation of the present state of the art and general trends in this country.     

Progress in display-device development in Western Europe

A review of the basic research and industrial development of display devices in Western Europe during the years 1968 to early 1973 will be given. The display types considered are: 1) active displays such as cathode ray tubes, light-emitting diodes, electroluminescence cells, and gas discharge devices, and 2) passive displays such as laser displays, light valves, and ferroelectric and liquid-crystal devices.